Comparative study of the gestational energy and protein balance of rabbit does

Authors determined the total body composition of 4x10 female, approximately 5-month-old New Zealand White rabbits, using direct chemical analysis and computerized tomography (CT). Ten non-pregnant rabbits and three times ten pregnant rabbits on days 14, 21, and 28 of gestation were investigated. With the advancement of pregnancy, the does' body weight increased significantly, while the dry matter content of the does' body slightly decreased (43.02 vs. 42.93, 40.77, and 40.94%). On the 28(th) day of pregnancy, the crude protein content of the pregnant does' body was significantly lower (20.15 vs. 18.13%, P(0.05), than that of the non-pregnant does. The same decreasing tendency could be observed during the pregnancy in case of ether extract (20.15 vs. 18.84, 19.04. and 18.13%) and ash content (3.06 vs. 2.88, 3.08, and 2.88%). With the advancement of pregnancy, the total energy content of the uterus and foetuses (1.75, 2.70, and 4.71% respectively) gave higher and higher proportion of the total energy content of does' body, but 5 percent of the energy level of total does body was not reached by that of the foetuses and uteri even at 28 days of pregnancy. According to the equations created from the CT pictures, body fat (R-2=0.871) and energy (R-2=0.926) content can be predicted with high accuracy. The accuracy of the prediction of body protein content is much lower (R-2=0.356), which can be improved by introducing the body weight as a new dependent variable (R-2=0.797). The foetal growth proved to be allometric. In contrast to other animal species, conceptus building in rabbits is not only considerable in the last trimester but also from the second half of the pregnancy.